In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. In 1920, Western Union has implemented the world's first transmission of images over the ocean. In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. In 2007 the company made 167.7 million transactions on money transfers between individuals and 404.6 million transactions between physical and legal persons. In October 1871 the company has implemented the world's first telegraph money order. After a century money transfers have become a major source of income for Western Union. In 1856, in 7 years after the foundation of New York State Printing Telegraph Company, the company changed its name to Western Union Telegraph Company. In 1884 Western Union has become a joint-stock company and was brought to the stock exchange. The company has entered in the first American stock index Dow Jones. Sibley, the founder of Western Union, did not build a new telegraph lines, and persuaded the other players to join. American Telegraph Company, however, still had to buy it.